iMessages
Why is my iPhone 13 Pro Max sending iMessages to a friend's Alcatel prepaid phone? They can't receive any of my texts because of this. I have to turn iMessage on and off in order to send texts to this person.
iPhone 13 Pro Max
iMessage is sent only between Apple Devices (iPhone/iPad/Mac/Watch)
If you are referring to SMS messaging then toggling iMessage On or Off will not affect SMS. Please contact your carrier if you have trouble sending SMS/MMS.